Abstract: Objective To evaluate the transdermal permeability of glucosamine sulfate solution across ex vivo rabbit dermis
under ultrasound and optimize the ultrasound conditions. Methods The ultrasound-assisted transdermal permeation of
glucosamine sulfate solution across ex vivo rabbit dermis was tested using a simple Franz diffuser. The transdermal permeation
volume and rate were calculated by measuring the concentration of glucosamine sulfate in the receptor fluid with ultraviolet
spectrophotometry, and the impact of different sound intensities, irradiation time and solution concentration on solution
permeation was analyzed. Results At the ultrasound intensity of 0.2 W/cm2, the permeation volume and rate of glucosamine
sulfate both reached the maximum; no glucosamine sulfate was detected in the receptor fluid after a 5-min ultrasound
irradiation. The permeation volume and rate of glucosamine sulfate increased as the irradiation time prolonged and also with
increased glucosamine sulfate concentration. The dorsal and lateral skin thickness (2.0±0.1 and 1.2±0.1 mm, respectively) did
not significantly affect the transdermal permeation of glucosamine sulfate (P>0.05). Conclusion Ultrasound irradiation at 1.0
MHz for over 5 min allows glucosamine sulfate to permeate rabbit dermis, and the volume and rate of permeation increase
with the irradiation time and concentration of the solution and are not affected by variations of the dermal thickness.